public static void bubbleSort(int [] a,int n){
    for(int i = 0; i < n-1  ; i++){
        for (int j = 0;j < n-1-i;j++){
            if(a[j] > a[j+1]){
                int temp = a[j];
                a[j] = a[j+1];
                a[j+1] = temp;
            }
        }
    }
}